A number of techniques are available for treating cardiovascular disease such as cardiovascular by-pass surgery, coronary angioplasty, laser angioplasty and atherectomy. These techniques are generally applied to by-pass or open lesions in coronary vessels to restore or increase blood flow to the heart muscle. In some patients, the number of lesions is so great, or the location so remote in the patient's vasculature, that restoring adequate blood flow to the heart muscle is difficult.
TMR has been developed as an alternative to these techniques which are directed at by-passing or removing lesions. TMR is preformed by boring channels directly into the myocardium of the heart. It has been found that creating several channels may be useful.
In one procedure, laser catheters are advanced into the left ventricle. Laser radiation is then focused on the myocardium to create a channel. Channels cut by a laser have a width proportionate to the width of the focused laser radiation used to make the channels.
TMR is also performed by cutting a channel with a sharpened probe or blade. When this procedure is performed with a blade, tissue is generally merely pierced or cut.
Lasers used to perform TMR can be costly and the depth of the channels formed can be difficult to control. Similarly, controlling the depth of the channels formed by a blade has been difficult to control.